Even today's atmospheric levels of greenhouse gases such as carbon dioxide are high enough to cause a global increase in temperature of between 2 and 2.4 degrees Celsius. (spiegel.de)
These adjustments would account for all of the recorded 0.6 C increase in temperatures in the 20th century. (realclimate.org)
You have to be a bit of a drama queen to interpret a few degrees increase in temperature over the span of a century as a catastrophe. (nofrakkingconsensus.com)